Community Forums

Gary - K7GLD · 08-27-2009, 09:22 AM

Thanks again Jim - the distributor seems fine as far as mechanical and vacuum advance functions, but found an EXCELLENT source for brand NEW, COMPLETE high output performance distributors on Ebay for $42.50:

BBC BIG BLOCK CHEVY 396 454 65K HEI DISTRIBUTOR 6500-R:eBay Motors (item 370244095348 end time Sep-23-09 11:30:00 PDT)

so will eventually play around with that, and see what I can come up with - for now, will simply set base timing to 8 degrees, and see what that accomplishes before proceeding further.

Thanks again - you WILL be hearing more from me, no doubt!

Tinman86 · 08-30-2009, 08:53 AM

Gary,

Please let us know how this distributor works out.

I am thinking of doing the same thing based on getting some results

Seon · 09-28-2009, 05:42 PM

Quote:

Originally Posted by Gary - K7GLD

I would think this would be a pretty common subject, but a search didn't seem to surface anything relevant, so here goes:

.. .the MPG really sucks at a bit over 5 MPG with careful driving at 55 MHH or so -

I thought my '84 Chieftain was getting lousy miles at 8 mpg but 5 mpg.. wow

Gary - K7GLD · 10-28-2009, 12:28 PM

I figured a bit of update might be in order...

Pretty well finished all but the most trivial of fixes and upgrades - the new Bilstein heavy duty RV shocks were (naturally!), a huge improvement over the 20 year old, failed OEM units - they, and the also new Bilstein steering stabilizer have substantially improved ride and steering quality. The steering is far more stable under widely varying road and traffic conditions, but even though the steering linkage and suspension all seems nice and tight at 58K miles on the clock, there is still a minor tendency to wander, and I suspect a front wheel alignment and/or different tires may well correct that as well - wonder if any others here have any first-hand experience with that?

Haven't installed the new distributor yet, want to experiment a bit with timing on the OEM unit, as well as a new set of sparkplugs first - and this RV season is dead in the water, so actual driving sessions will have to wait until Spring. Fuel MPG at 7 MPG in steep grade, high elevation mountain driving MIGHT not be too bad, IF it actually gets better out in the flat lands.

My newly installed tachometer reveals that RPM at about 55 MPH is 2500 RPM or so - not sure if that is typical or ideal for a GM big block engine or not - but seems about as high as I'd want to maintain over long distance travel for MPG and engine reliability - any comments on that one?

No apparent over the counter rebuilt/recurved distributors or carburetors have surfaced, so will limit work in that area to my own slow pace when I can once again get the MH back on the road for further testing - but all is looking much improved so far - and thanks to all here for their suggestions and help!

Oldvet · 10-31-2009, 02:10 PM

Quote:

Originally Posted by Seon

I thought my '84 Chieftain was getting lousy miles at 8 mpg but 5 mpg.. wow

That`s what i`m averaging with my 85 31 foot Chieftain, got 8.5 once going across Oklahoma with a 30 mph tail wind.

Gary - K7GLD · 11-01-2009, 10:03 AM

Quote:

Originally Posted by Oldvet

That`s what i`m averaging with my 85 31 foot Chieftain, got 8.5 once going across Oklahoma with a 30 mph tail wind.

Quote:

I thought my '84 Chieftain was getting lousy miles at 8 mpg but 5 mpg.. wow

Sounds good guys - but bring those rigs out MY way - where pretty much ALL my normal RV travels (usually a 100 mile round trip to our favorite CG and fishing spot) involve about 40 miles of steep grade, mile-high mountain passes, and narrow 45 MPH roads with LOTS of sharp curves, THEN we'll compare MPG!

Dunno WHAT MPG this rig would get out in flat, low elevation country - our "average" elevation here is about 3500 feet - but my last MPG check at 7 MPG in MY conditions, just MIGHT not be all that bad!

HEY - "We ain't in KANSAS any more, Toto!"

.

JimElliott · 11-01-2009, 11:18 AM

7 MPG crawling around the hills ain't bad at all IMHO, Any way I drive out of the Coachella valley (Palm Springs) it's nothing but hills....
It's 35 or so miles east bound (I-10) to reach decently level ground but the altitude is below 3,000 feet and yes I'm at sea level....
I've got a week to 10 days to play and reservations at Tombstone Arizona have been made, Up hill all the way from here BUT downhill on the way back.
Cool weather (no A.C.) or generator running will save me 1 gallon per hour and it is a 8 hour drive, Still HAVE NOT trimmed out the slightly over rich idle condition bvut when the cool of winter arrives it shall be done...

Jim

Oldvet · 11-01-2009, 01:16 PM

I`m pretty happy with 8 mpg, we had a 79 ford class C years ago and that`s all it got. So for something with a lot more room i`m happy, when we crossed Iowa we bucked at least a 30 mph wind and still got 7.5 mpg. I`m guessing i`d get around six in steep hills.

Gary - K7GLD · 11-01-2009, 03:18 PM

WELL, my hesitation to expect better MPG under lower elevation and more level terrain, is based upon the old '76 Winnebago we had with the 440 Dodge - terrain, wind, or NOTHIN' seemed to affect the 5 MPG we got with that thing - great power, but economy sucked! SO, while I'd *like* to expect better economy under better travel conditions, I'll just have to wait and see.

I mentioned about my 2500 RPM at 55 MPH - what is considered a decent cruising RPM for these GM BB engines for reasonable MPG and engine life in heavy duty service? AND, also, have any others noticed any significant steering "wander" caused by either alignment, or perhaps tire type/tread design? Can inflation PSI make significant difference - I'm running 75 PSI on all tires.

I have pretty new Bridgestone steel belted radials all around, and still have a small degree of wander remaining after replacing all shock absorbers and steering stabilizer with heavy duty Bilsteins - FAR better than before, and maybe I'm just expecting too much from a barn on wheels?

Oldvet · 11-01-2009, 04:50 PM

Quote:

Originally Posted by Gary - K7GLD

WELL, my hesitation to expect better MPG under lower elevation and more level terrain, is based upon the old '76 Winnebago we had with the 440 Dodge - terrain, wind, or NOTHIN' seemed to affect the 5 MPG we got with that thing - great power, but economy sucked! SO, while I'd *like* to expect better economy under better travel conditions, I'll just have to wait and see.

I mentioned about my 2500 RPM at 55 MPH - what is considered a decent cruising RPM for these GM BB engines for reasonable MPG and engine life in heavy duty service? AND, also, have any others noticed any significant steering "wander" caused by either alignment, or perhaps tire type/tread design? Can inflation PSI make significant difference - I'm running 75 PSI on all tires.

I have pretty new Bridgestone steel belted radials all around, and still have a small degree of wander remaining after replacing all shock absorbers and steering stabilizer with heavy duty Bilsteins - FAR better than before, and maybe I'm just expecting too much from a barn on wheels?

I`m no expert by no means with these outfits and will only say what i`m doing and effects from it.
My 85 Winny 31 footer drives like a new car, i was amazed on how well it handles. I have new tires and am running 95 in the front and 100 in the rear. My rig has air bags up front with 75 lbs in them.
As far as rpm mine seems to screem pretty good at 60 and i preffer to not drive faster than that. These back roads here in TX are marked 70 and it would scare me to drive this old rig that fast over some of the dips and bumps.

JimElliott · 11-01-2009, 06:38 PM

Quote:

Originally Posted by Oldvet

I`m no expert by no means with these outfits and will only say what i`m doing and effects from it.
My 85 Winny 31 footer drives like a new car, i was amazed on how well it handles. I have new tires and am running 95 in the front and 100 in the rear. My rig has air bags up front with 75 lbs in them.
As far as rpm mine seems to screem pretty good at 60 and i preffer to not drive faster than that. These back roads here in TX are marked 70 and it would scare me to drive this old rig that fast over some of the dips and bumps.

Oldvet & Gary, The RPMs hang around 3,000 @ 62 MPH on mine and I would suspect both of you are pretty close also....
When the need to pass one of those 300 under powered horse diesels struggling up the hills I simply punch it and for a few moments the RPMs climb to 3,600 or so and the speed zips to 70 MPH...
My 83 is another good handling rig...

Jim

Oldvet · 11-01-2009, 06:46 PM

Harley finally got smart and went to a six speed, these rigs could use another gear on flat ground at todays speeds.

Sammie · 11-01-2009, 07:06 PM

Gary, if you still experiance steering wander you might want to check out one of these Track Bars. I put one on my 2000 Adventurer workhorse chassis and it made a day and night difference.

SuperSteer® Trac Bars»SuperSteer For RV Owners

Sammie

Gary - K7GLD · 11-01-2009, 08:22 PM

Thanks for the RPM info - I'm sorta used the the power of my '02 Dodge/Cummins with the 6-speed manual tranny, towing our 24 foot 5er - about the same GCW as the GVW of the Winnie - but NO comparison in power or economy. The Dodge 5er combo easily pulls all our passes here, in O/D if I choose - with power to spare, runs about 1800 RPM at 60 MPH, and delivers over 17 MPG in mixed mountain/flatlands travel. I suppose the power add-ons that put me at 420 HP and nearly 1000 ft. lbs. tq on the dyno might have a LITTLE bit to do with that

Sure wish I had a Cummins and tranny like that in the Winnie...

Quote:

Originally Posted by Sammie

Gary, if you still experience steering wander you might want to check out one of these Track Bars. I put one on my 2000 Adventurer workhorse chassis and it made a day and night difference.

SuperSteer® Trac Bars»SuperSteer For RV Owners

Sammie

Sammie, that sounds like a decent gadget - but the minor tendency I'm experiencing, is not instability from the REAR of the MH, or caused by traffic, wind or similar conditions, just a small tendency on straight, smooth roads to not hold a steady straight line. Of course, other conditions undoubtedly make it a bit more noticeable, but all the new shocks pretty well took care of all that.

My thinking was that maybe the tread design of the tires, or slight misalignment of the front end might contribute. I also have airbags front and rear - 90 PSI rear, 70 front, as per the maker's instructions.